Following the unsuccessful appeal against Alan Quinlan's three-week suspension for stamping, which rules him out of the Ireland squad for Saturday's game against Argentina, Donnacha Ryan has been included among the replacements.
The 24-year-old Ryan played the full 80 minutes in Munster's heroic defeat to the All Blacks at Thomond Park on Tuesday.
Comfortable in the second row or back row, he was part of the Ireland 'A' squad that won the Plate title at last summer's Churchill Cup tournament.
Ryan is now on the cusp of earning his first senior cap and his rise into the Test ranks is all the more impressive given that he only started playing rugby as a 17-year-old in Nenagh.
IRELAND TEAM & REPLACEMENTS (v Argentina, GUINNESS Series 2008, Croke Park, Saturday, November 22, kick-off 2.45pm):
15 - Geordan Murphy (Leicester Tigers)
14 - Tommy Bowe (Ospreys)
13 - Brian O'Driscoll (UCD/Leinster) (capt)
12 - Luke Fitzgerald (Blackrock College/Leinster)
11 - Rob Kearney (UCD/Leinster)
10 - Ronan O'Gara (Cork Constitution/Munster)
9 - Tomas O'Leary (Dolphin/Munster)
1 - Marcus Horan (Shannon/Munster)
2 - Jerry Flannery (Shannon/Munster)
3 - John Hayes (Bruff/Munster)
4 - Donncha O'Callaghan (Cork Constitution/Munster)
5 - Paul O'Connell (Young Munster/Munster)
6 - Stephen Ferris (Dungannon/Ulster)
7 - David Wallace (Garryowen/Munster)
8 - Jamie Heaslip (Naas/Leinster)
Replacements:
16 - Rory Best (Banbridge/Ulster)
17 - Tony Buckley (Shannon/Munster)
18 - Malcolm O'Kelly (St. Mary's College/Leinster)
19 - Donnacha Ryan (Shannon/Munster)
20 - Eoin Reddan (London Wasps)
21 - Paddy Wallace (Ballymena/Ulster)
22 - Keith Earls (Young Munster/Munster)